Inside Hogwarts, coming down the stairs is Sirius Black, a determined look in his eyes as he's heck ready to give hell at those darned Death Eaters. He remembered what he had learned over the past months, thanks to Dobby's cleaning out.
Dobby and the other House elves piled out everything from the Room of Requirement into one of the rooms of Harry and Sirius's Wizarding Tent, having 3 bedrooms, a office, a kitchen, and a bathroom, and a living room. There were quite some unique books, and quite a lot of junk, useful things, and more. Figuring that the other Wizarding Tents can be used by Ron and Hermione, and any other future residents, they pulled out all the books from the Tents' libraries, building one sole building from stone and wood, enlarging the inside while on the outside, being like a stall in retro-respect.
Once, in Sirius and Harry's secret adventures in the muggle world, they saw the cartoon movie of Beauty and the Beast, and this library that the boys built is based upon that humongous library in Beast's castle. They contacted the goblins through Dobby with a new communication mirror that the boys found from the pile. With the signatures of the boys upon paper, they had Dobby and Kreacher, and several Potter Elves take all the books, compartment trunks, and wizarding portraits for Harry to know his family, through his parents didn't have one themselves unfortunately, from all the Black, Potter vaults, leaving the gold, jewelry alone, knowing how the goblins love and fight over gold.
Sirius learned a lot from Henry in farming, and so hence the fields they made upon the plateau. After Dobby found the Vanishing Cabinets, Ron and Hermione visited immediately, and they fell in love with everything that Harry told them about, and to their surprise, they became godparents of Odette, as Sirius is already a uncle to Odette. With Spot and his family as muggleborns, they soon came to be living in a magically made hut in the forest nearby, thanks to the others' help.
Hermione instantly found a solution to the water problem for both Spot's family, which is now called 'The Nomads', you know, Spot Nomad, Willy Nomad, so on, and both the Jurassic Plateau family which contists of Harry, Sirius, Hedwig, Odette. Being a studious student, and reading the books in the Jurassic Library, she found a way to pave the way for a dug well to the water and back to the surface.
And Ron, seeing that the rocks from the plateau to Clawtooth Farm is very irritating and annoying to his feet and everyone else's feet, which he and Hermione got to know the family at, he remembered the muggle town and how it was small, having bikes and very few cars, the town used only a wide road in and out, and Ron gave a solution for the rocky problem, shockingly reading a book for that, and with everybody's help, including the Clawtooth family as well, they paved the earthy, simple road.
Sirius was proud of everyone, knowing that teenagers are more resourceful than any adult could be. He also was delighted when he found a unknown Animagus book which was written by the Founders, and as Hermione's great with potions, she and Sirius made quite a few, and to everybody's shock and amusement, Harry was found to be a Dilong, a raven-feathered dinosaur with amber gold eyes at 25 pounds. Hermione discovered that she is a beautiful russet fox with chestnut brown eyes, while Ron got excited to find out that he's a golden lion with dark blue eyes, through it's of the mane-less species.
And with a specific potion from the Animagus book, Sirius's Grim-like dog form got much bigger, basically around the size of a large horse, so he basically hunted occasionally with Butch, and his family, and battled as well, knowing too well that he can take over a human easily now. And now he's out here in his old world.
Down on the ground floor besides the Great Hall, a Remus Lupin is fighting Death Eaters left and right, and his sensitive ears heard screams a distance away, a roar-like growl, and suddenly as he was fighting a stubborn Death Eater, a enormous black dog tore into the man, earning Remus to freeze and stare in awe and shock, and the dog, done with the man, stared at Remus, and somehow grinned widely, shifted back into a human being that Remus never thought to see again.
"P-Padfoot?". Remus asked in a whisper, and Sirius aka Padfoot smiled softly, "Hey, Moony. I really missed you, old friend. Mischief Managed, right?". Remus then exhaled, realizing that his old best friend is really alive and standing in front of him, "You better tell me the details later, Sirius, but now, we have to kick some ass.". He smirked, swearing a bit, earning Sirius to laugh and cast some spells out in a split second, causing the two Marauders to jump back in battle instantly.